Writer-director Jill Sprecher, in collaboration with her sister, screenwriter Karen Sprecher, attempts something very difficult in "13 Conversations About One Thing." That she succeeds to the extent she does -- say, 80 percent -- is a major achievement.

What's exciting is that the Sprechers have delved into territory that is normally the domain of literature and have emerged with a film that's neither overly literary nor simplistic. "13 Conversations" makes a case for cinema as a vehicle for conveying moods and ideas and, hardest of all, the internal movements of a soul. If that doesn't sound like much, just imagine trying to capture the movements of a soul on camera.

In "13 Conversations," Sprecher doesn't just do that once. She does it repeatedly, in a film with an ensemble cast and a screenplay made up of interconnected and interweaving stories.

Most of the film's characters are suffering from a form of depression. John Turturro plays a physics professor in a burnt-out marriage. When he comes home to dinner with his wife (Amy Irving), the feeling in the air is not one of recrimination but of utter exhaustion. It's so quiet in that apartment they can hear themselves age.

The conversations are all about happiness, how to get it, how to keep it, how to lose it. Matthew McConaughey is a hotshot young lawyer who meets a sour insurance executive (Alan Arkin) in a bar. The lawyer believes he can make his own luck. The insurance man is fatalistic, seeing life as a kind of rigged game. Subsequent events prove both of them wrong.

If any one actor is at the center of the film it's Arkin, who plays a bitter claims adjuster, Gene, who develops a hostile fixation for one of his employees, Wade (William Wise), a fellow with an inborn gift for happiness. Gene needs to convince himself that Wade is an idiot. It's either that or admit that he has misspent his own life.

The Sprechers are on to something. They're about showing the real pain of real people. "13 Conversations About One Thing" is their artistic breakthrough. - This film contains sexual situations and strong language.